body {
  background-image: url(https://i0.hippopx.com/photos/683/318/324/wolf-wolves-snow-wolf-landscape-preview.jpg);
}
.task {
  background: hsl(0, 100%, 25%);
}
.tast {
  background: hsla(0, 100%, 25%, 0.25);
}
ul {
  list-style-type: square;
}
/* 字体大小的属性值出现在设置字体系列的前面，如果有行间距的话，行间距必须直接出现在字体大小后面，用斜杠连接。 */
h1 {
  font: bolder 25px "隶书";
  text-align: center;
}
h1 span {
  font-style: italic;
  text-decoration: underline;
  text-shadow: 0 0 5px #fff, 0 0 10px #fff, 0 0 15px #fff, 0 0 40px #ff00de,
    0 0 70px #ff00de;
}
.happy {
  height: 250px;
  width: 250px;
  background-color: lightcoral;
  background-image: url(https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1583164965879&di=f5a46571f4a2b4ba35f7787e400a9ca0&imgtype=0&src=http%3A%2F%2Fforumpic.hmlan.com%2Fpics0002%2F2012-4%2F201242111920_a1b36184.gif);
  background-position: center;
  background-repeat: no-repeat;
}
#practice {
  height: 250px;
  width: 250px;
  background-color: rgba(204, 204, 204, 0.479);
  margin: 5px 10px;
  border: 3px rgb(52, 121, 52);
  border-style: dashed;
  padding: 20px;
  padding-top: yellow;
}
#practice p {
  color: red;
  background-color: lime;
}
.deg {
  width: 300px;
  height: 300px;
  background-color: rgba(202, 186, 13, 0.8);
  margin: 60px;
  border-top: 5px rebeccapurple solid;
  padding-top: 50px;
}
